JorgeB

Also see here: https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=819173

That error by itself is not necessarily a problem, see if you can get the diags, from the tools -> diagnostics on the GUI or by typing diagnostics on the console.

There are errors on 4 disks, likely a connection issue.

If you want you can do a new config to reset the array and assign a single drive, make sure you take note of current assignments, in case you want to keep them the same for later.

Like suspected there's no key and can't be get from the array. Mar 4 11:48:49 Tower unassigned.devices: luksOpen: key file not found - using emcmd to open. Mar 4 11:48:51 Tower unassigned.devices: Mount drive command: /sbin/mount -o rw,noatime,nodiratime '/dev/mapper/ST6000DM003-2CY186_WCT2Z4WV' '/mnt/disks/ST6000DM003-2CY186_WCT2Z4WV' Mar 4 11:48:51 Tower unassigned.devices: Mount of '/dev/mapper/ST6000DM003-2CY186_WCT2Z4WV' failed. Error message: mount: /mnt/disks/ST6000DM003-2CY186_WCT2Z4WV: special device /dev/mapper/ST6000DM003-2CY186_WCT2Z4WV does not exist. Mar 4 11:48:51 Tower unassigned.devices: Partition 'ST6000DM003-2CY186_WCT2Z4WV' could not be mounted. If you start the array, even using a single encrypted disk, it should mount after that.

Yes Likely because of the encryption, UD uses the same key as the array, and since array is not started I suspect that's the problem, but would nee the syslog to confirm.

The primary superblock will be destroyed, you can have xfs_repair look for a backup one and see if it was up to date, but IMHO best bet would be to ask for help on the xfs mailing list.

Raid0 also wouldn't use the full available space, see here for more info. Docker image is a single file, it can't be split to the array, appdata can use the array if the minimum free space settings is correctly set, though not really recommended to split appdata between cache and array. https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=480419 Explained on the first link posted above.

I meant swap slots, this way you can at least rule that out if the same disk fails again.

Not that surprised since the disk problems didn't look like bad sectors, but that the disk sometimes was slow or not even initialized correctly. After the new config you'll be asked for the encryption key/passphrase.

16MB/s is on the slow side even for normal write mode, but at least for the initial loading you want to use turbo write.

If the server reboots during a check you very likely have some hardware problem, make sure it's not overheating and then test with hardware, like a different PSU, etc

Those don't really help, did you:

Yes, but I recommend first mounting the disk with UD just to make sure it's mounting and data looks correct or the rest of this would be pointless, if all looks good you'd need to: -Tools -> New Config -> Retain current configuration: All -> Apply -Unassign old disk -Assign new disk (the ddrescue dest) -Start array to begin parity sync -New disk won't mount because of "invalid partition" Once the parity is synced: -stop array -unassign the disk -start array -emulated disk should now mount correctly -stop array -re-assign disk to rebuild on top

Easiest way would be to unassign that disk, start the array, then re-assign it to rebuild, assuming parity exists and is valid.

There are some reallocated sectors, never a good sign but if it remains stable it might be OK, good idea to run an extended SMART test though.

You can still mount it with UD then copy data to the array, Unraid won't accept it since partition won't be using the full disk, you could sync parity with the disk unmountable then rebuild, partition would be correctly recreated during that, but it will take longer. Install the nerdpack plugin, you can then installed screen there.

I didn't check that and wile theoretically you can have 2GB/s with a x4 link in practice it will max out at 1.5GB/s at best, so good catch by @Bensonand make sure the HBA is installed in a x8 slot.

Yes, you can re-sync with the new parity drives, array will be unprotected during the sync, but it will be the same if you re-sync to the older parity drives. Yes, assuming the disk is still working/healthy, obviously any read errors will result in lost data. Yes.

Tool -> new config -> keep all assignments Then unassign old disk and assign new one in its place (new disk need to be same capacity as the old one to be used in the array) Check "parity is already valid" before stating array (but if there are errors on ddrescue a parity check will be needed) You'll need to restart, using "screen" can get around that.

It is, I can only tell that I never got it.

In raid10 only 3TB will be usable with that pool, see here: https://carfax.org.uk/btrfs-usage/

Sync errors were already corrected, they were only on Parity2, which is strange unless there's an explanation. As for disk5, it dropped offline so there's no SMART, check connections and post new diags after that.

Errors look like a connection problem, most likely the SATA cable since CRC errors went up, you would be notified of that if system notifications were enable.